Pakistan, May 4 -- American swimmer Gretchen Walsh has stormed to 54.33 seconds in the women's 100-metre butterfly to lower her own world record for the fourth time at the Fort Lauderdale Open in Florida, the United States.

Walsh on Saturday sliced 27-hundredths of a second off the previous world record of 54.60 she set in the same pool at a Pro Swim event last May. She broke the record twice in one day at last year's meeting and has now broken the record four times. Winner of three world titles in Singapore last year, Walsh is now more than a second faster than the second-fastest woman in the history of the event, with Sweden's Sarah Sjostrom at her best of 55.48 seconds.

She was more than four seconds faster than world junior record h...